refactor(utils): one PgTextString for the four pgtype.Text unwrappers

handlers textToString, router textToString, router getText, and utils
normText were four copies of the same NULL-to-empty unwrap (99 call
sites). One exported utils.PgTextString replaces them all; the private
normText (comparison normalizer) stays but is now the odd one out.

Harness fix found on the way: setupTestServer built a full wiring
literal for route registration and then RETURNED a second, sparser
literal that never copied AnnotationService — setup.AnnotationService
was always nil on the struct every test receives. Nobody noticed until
cross_library_move_test became the first caller (it previously used
the now-retired plain CreateMediaHighlight query); it now exercises
the real SaveHighlight path through the wired service.

internal/router/helpers.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"bookhoard/internal/database"
+	"bookhoard/internal/utils"
 	"bookhoard/templates"
 
 	"github.com/google/uuid"
@@ -60,8 +61,8 @@ func getTemplateUserWithTheme(c *echo.Context, cfg *Config) (templates.User, err
 		Theme:     userTheme,
 		Token:     token,
 		Timezone:  userTimezone,
-		FirstName: getText(userDB.FirstName),
-		LastName:  getText(userDB.LastName),
+		FirstName: utils.PgTextString(userDB.FirstName),
+		LastName:  utils.PgTextString(userDB.LastName),
 		CreatedAt: userDB.CreatedAt.Time,
 	}, nil
 }
@@ -135,13 +136,6 @@ func folderReachableCached(path string) bool {
 	return exists
 }
 
-func getText(t pgtype.Text) string {
-	if t.Valid {
-		return t.String
-	}
-	return ""
-}
-
 func resolveLibrary(c *echo.Context, cfg *Config, userUUID string) LibraryResolution {
 	res := LibraryResolution{}
 
@@ -195,7 +189,7 @@ func resolveLibrary(c *echo.Context, cfg *Config, userUUID string) LibraryResolu
 		res.Libraries[i] = templates.LibraryData{
 			ID:          libUUID.String(),
 			Name:        lib.Name,
-			Description: getText(lib.Description),
+			Description: utils.PgTextString(lib.Description),
 			TypeName:    lib.TypeName,
 			TypeValue:   lib.TypeName,
 			MediaCount:  countMap[libUUID.String()],